The present invention relates to a method for making a design reference and an apparatus therefor, and more particularly to a method for making a design reference and an apparatus therefor suitable for interactively and comparatively checking the validity of a layout plan of components of a design object.
An apparatus for making a design reference (hereafter referred to as a CAD apparatus) comprises a display screen on which a design object is to be displayed and an input device for generating coordinate data based on the designation of a point on the display screen in order to display a point, line or characters at the designated point and write a coordinate of that point and the displayed data into a memory by using an interactive technique. Such an apparatus is disclosed in the U.S. Pat. No. 4,451,895.
In the prior art CAD apparatus, data of a design object is converted to image data in order to display it on a display screen, and comparative checking of the design object is done by visually watching the data on the display. For example, in a CAD apparatus disclosed in Japanese Application JP-A-59-17382, scaled orthogonal lines are displayed on a display screen. An operator watches the orthogonal lines to visually measure a distance between two points on the screen. A CAD apparatus disclosed in Japanese Application JP-A-60-3791 recognizes a vector related to a point on a display screen which an operator picked.